Method and system for controlling the quality of a stamped part

Abstract

A system and method for detecting a defective part and the type of defect formed during stamping operations. The system and method will not only detect the defect but also the nature of the defect and the time at which the defect occurred during stamping operations. Such information is useful not only in quality control but also in isolating a problem which may exist in stamping operations and thus eliminating time for isolating such problems and correcting them. The system and method uses a profile of a properly stamped part to detect a defect, and the root cause of the defect.

1 . A system for detecting a defect in a part stamped from a blank of material, the system comprising:
 a die having a slide press, a die cushion;   a sensor operable to detect the forces applied to the blank of material;   a database having a profile of having a characteristic of forces of a properly stamped part;   a processor in communication with the sensor, the processor comparing the forces detected during the stamping of the part, and labeling the part defective when the detected forces deviate from the profile of the properly stamped part.   
     
     
         2 . A system as set forth in  claim 1 , further including an encoder disposed on one of either the slide press or the cushion press, the encoder operable to detect the position of the respective slide or cushion press during die operations. 
     
     
         3 . A system as set forth in  claim 1 , wherein the sensor is a plurality of sensors each of the plurality of sensors is disposed along respective corners of both the slide and cushion press. 
     
     
         4 . A system as set forth in  claim 1 , wherein the profile includes peak forces of the slide and cushion press with respect to time, and the work performed by both the slide and cushion press. 
     
     
         5 . A system as set forth in  claim 2 , wherein the profile includes the position of both the slide and cushion press during the stamping operations with respect to time. 
     
     
         6 . A system as set forth in  claim 1 , further including an automatic shut-off operable to cease operation of the die, the processor actuating the automatic shut-off when the detected forces deviate from the profile of the properly stamped part. 
     
     
         7 . The system as set forth in  claim 1 , wherein the profile further includes a force parameter, wherein parts stamped having forces outside of force parameter are labeled as defective. 
     
     
         8 . The system as set forth in  claim 1 , further including a defective profile, the defective profile including the force characteristics of a defective part, and the nature of the defect. 
     
     
         9 . The system as set forth in  claim 8 , wherein the defective profile further includes the root cause of the defect. 
     
     
         10 . A method for detecting a defect in a part stamped from a blank of material formed by the operation of a die, the method comprising:
 establishing a profile, the profile having a characteristic of forces of a properly stamped part;   measuring the forces of the stamped blank of material;   comparing the force characteristics of each of the stamped blank of material with the profile of the properly stamped part; and   labeling any of the stamped blank of material as being a defective part when the forces deviate from the profile of the properly stamped part.   
     
     
         11 . The method as set forth in  claim 10 , wherein the base line includes a slide force and a die cushion force. 
     
     
         12 . The method as set forth in  claim 11 , further including the step of establishing a slide force parameter, wherein stamped material having slide forces outside of the slide force parameter are labeled as defective. 
     
     
         13 . The method as set forth in  claim 11 , further including the step of establishing a cushion force parameter, wherein stamped material having cushion forces outside of the die cushion force parameter are labeled as defective. 
     
     
         14 . The method as set forth in  claim 10 , further including the step of using the speed of the die operation to establish the profile. 
     
     
         15 . The method as set forth in  claim 10 , further including the step of using the temperature of the die to establish the profile. 
     
     
         16 . The method as set forth in  claim 10 , further including the step of placing a film of oil on the blank of material, and establishing the profile based upon the film of oil placed on the blank of material. 
     
     
         17 . The method as set forth in  claim 10 , further including the step of establishing a defective profile, the defective profile including the force characteristics of a defective part, and the nature of the defect. 
     
     
         18 . The method as set forth in  claim 17 , wherein the defective profile further includes the root cause of the defect.